A medicament delivery device includes a housing adapted to receive a medicament container； an actuation member movable from a first position to a second position, such that the medicament is allowed to be expelled through the delivery member； and an interlock member movable between a locking position and a releasing position. The device has an indicator to show that it has been used provided by the actuation member's being retained in its second position. The actuation member includes at least one latching projection, and the drive mechanism includes corresponding latching surfaces, against which the latching projections latch when the actuation member is in its second position.
